API Documentation for: 1.0.0
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File:promote.js

/*
* promote
* Visit http://createjs.com/ for documentation, updates and examples.
*
* Copyright (c) 2010 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/

/**
 * @module CreateJS
 */

// namespace:
this.createjs = this.createjs||{};

/**
 * @class Utility Methods
 */

/**
 * Promotes any methods on the super class that were overridden, by creating an alias in the format `prefix_methodName`.
 * It is recommended to use the super class's name as the prefix.
 * An alias to the super class's constructor is always added in the format `prefix_constructor`.
 * This allows the subclass to call super class methods without using `function.call`, providing better performance.
 *
 * For example, if `MySubClass` extends `MySuperClass`, and both define a `draw` method, then calling `promote(MySubClass, "MySuperClass")`
 * would add a `MySuperClass_constructor` method to MySubClass and promote the `draw` method on `MySuperClass` to the
 * prototype of `MySubClass` as `MySuperClass_draw`.
 *
 * This should be called after the class's prototype is fully defined.
 *
 * 	function ClassA(name) {
 * 		this.name = name;
 * 	}
 * 	ClassA.prototype.greet = function() {
 * 		return "Hello "+this.name;
 * 	}
 *
 * 	function ClassB(name, punctuation) {
 * 		this.ClassA_constructor(name);
 * 		this.punctuation = punctuation;
 * 	}
 * 	createjs.extend(ClassB, ClassA);
 * 	ClassB.prototype.greet = function() {
 * 		return this.ClassA_greet()+this.punctuation;
 * 	}
 * 	createjs.promote(ClassB, "ClassA");
 *
 * 	var foo = new ClassB("World", "!?!");
 * 	console.log(foo.greet()); // Hello World!?!
 *
 * @method promote
 * @param {Function} subclass The class to promote super class methods on.
 * @param {String} prefix The prefix to add to the promoted method names. Usually the name of the superclass.
 * @return {Function} Returns the subclass.
 */
createjs.promote = function(subclass, prefix) {
	"use strict";

	var subP = subclass.prototype, supP = (Object.getPrototypeOf&&Object.getPrototypeOf(subP))||subP.__proto__;
	if (supP) {
		subP[(prefix+="_") + "constructor"] = supP.constructor; // constructor is not always innumerable
		for (var n in supP) {
			if (subP.hasOwnProperty(n) && (typeof supP[n] == "function")) { subP[prefix + n] = supP[n]; }
		}
	}
	return subclass;
};